Voltage regulating apparatus for electric current generators



juiy 2-7, 1937. P. CIBIE 2,088,289

VOLTAGE REGULATING APPARATUS FOR ELECTRIC CURRENT GENERATORS Filed JUIIQ 12, 1954 HgrlI INVENTO E PIERRE C,

Patented July 27, 1937 UNITED STATES PATENT OFFICE Pierre Cibi, Paris, France Application June 12, 1934, Serial No. 730,222 In France June 21, 1933 1 Claim.

This invention relates to a voltage regulating apparatus for electric current generators.

An object of the present invention is the provision of a voltage regulating apparatus which may be used for different types of dynamos and which will be extremely responsive and sensi tive.

The above and other objects of the present invention may be realized through the provision of a regulating device having a secondary winding which is shunted to the terminals of a noninductive resistance or upon a part of such resistance which itself is shunted to the terminals of the dynamo inductor.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing showing a preferred embodiment of the inventive idea.

In the drawing:

Figure 1 is a diagram showing a device known in prior art.

Figure 2 is a diagram illustrating the strength of the current.

25 Figure 3 illustrates diagrammatically a device constructed in accordance with the principles of the present invention.

Voltage regulating apparatus for electric current generators of the type diagrammatically illustrated in Fig. 1 of the appended drawing are well known. The circuit of the inductors i of the generator is normally closed by the carbon contact c.

When the voltage at the terminals is higher than the voltage for which the regulating apparatus has been adjusted the blade :2 is attracted. Owing to the self induction of the inductors the passage of the current is not instantaneously interrupted, but is kept up by a spark between the two contact parts c of the regulating device.

The winding e which has a low self induction relatively to its resistance and is branched at the inductor terminals takes up a portion of this supplementary current, but owing to its own self induction it does not absorb it as completely as a real resistance would do.

Owing to the decrease of the current in said winding or even to its total reduction resulting from the opening of the contact pieces, the attraction caused by said winding decreases.

The voltage of the dynamo decreases simultaneously as well as the attraction caused by the primary winding 6 and the blade rises again rapidly under the action of the spring r owing to (Cl. 17l-222) the simultaneous decrease of both attractions.

The above device has the two following chief disadvantages:

1st.The secondary winding e being located immediately at the terminals of the inductors, the electric current that passes through it is a function of that which flows through the inductors and consequently depends upon the construction of said inductors. This has the drawback of requiring an adjustment of the regulating device for each type of dynamo.

2nd.The secondary winding .having an important self induction does not easily take up the supplementary current from the inductors and said supplementary current generates at the terminals of the contact piece 0 a considerable electromotive power which ensures the passage of the spark when the contact pieces are at a considerable distance apart, thus causing very important displacements of the blade and in some cases the persistence of the spark.

Said displacements of the blade reduce the frequency of its vibrations.

It will be seen from the diagram in Fig. 2 that when the frequency decreases the maximum strength of the current which has been reached during the operation of the regulator to produce the same mean strength in the inductors increases.

This increase of the maximum strength produces the increase of the power brought out in the spark at the disruptive moment and consequently results in a more rapid and profitless destruction of the contact pieces.

It will therefore be more advantageous to increase as much as possible the vibrating speed of the blade.

Fig. 3 of the annexed drawing illustrates diagrammatically the present improvement and re ferring to said figure it will be seen that the noninductive resistance R is branched at the terminals of the inductors i between two points of which the secondary winding e of the regulating device is branched. The other elements are the same as before.

At the moment when the blade p is attracted the supplementary current produced by the inductors is almost completely taken up by the noninductive resistance R. The electromotive power produced at the terminals of the contacts is low and the spark is very quickly put out. The current being annihilated in the circuit of the contacts, the voltage of the dynamo decreases immediately, the current in the secondary winding e also decreases and the blade immediately rises.

This mode of coupling results therefore in reduclng the amplitude of the mrvement oi the blade and in increasing the frequency of its vibrations.

This causes on the one part a reduction of the length oi the spark and on the other part, as seen in the diagram in Fig. 2, a reduction of the power brought out in said spark, so that the oxidation oi the contacts and all the resulting inconveniences are almost completely avoided. This allows of replacing he carbon contacts by metal contacts.

The secondary win ding e being moreover closed by a resistance, the current that passes through it is independent 0! the characteristic leatures of the dynamo in use so that the same regulating device is appropriate for all types of dynamos.

What I claim and desire to secure by Letters Patent oi the United States is:

A voltage regulating device for electrical generators comprising in combination with the armature and the inductor of a generator, said inductor having one end connected with one end of said armature; a contact comprising a stationary member and a movable member adapted to vibrate against said stationary member, said s ationary member being directly connected with the opposite end of said inductor, said movable member being connected with the opposite end of said armature, a non-inductive resistance connected to the first-mentioned end oi said inductor and connected to said stationary member, whereby said non-inductive resistance is connected in parallel withsaid inductor and in series with said stationary member, and an electro-magnet adapted to attract said movable contact member, whereby the current in the inductor is interrupted when said contact members are separated from each other, said electro-magnet comprising a primary winding connected in parallel with said armature and a secondary winding connected in parallel with at least a portion of said noninductive resistance.

PIERRE cnsns. 

